Structure and surface characteristics of Fe-promoted Ni/Al2O3 catalysts for hydrogenation of 1,4-butynediol to 1,4-butenediol in a slurry-bed reactor†
A series of nanostructured Ni–xFe/Al2O3 catalysts with different Fe doping concentrations (x = 0, 1, 3, 5, 7 and 9 wt%) were prepared by the sol–gel combustion (SGC) synthesis method. The Ni/Al2O3 catalysts with introduced Fe exhibited higher activity and stability for the hydrogenation of 1,4-butynediol to 1,4-butenediol, compared to Ni/Al2O3. The effects of Fe loading on the physicochemical properties of Ni/Al2O3 catalysts as well as their catalytic performances for 1,4-butynediol hydrogenation to 1,4-butenediol were studied in detail. The improved catalytic performances of Ni–xFe/Al2O3 over that of Ni/Al2O3 were ascribed to the varied metal–support interaction and active site dispersion, as well as the formation of NiFe2O4. Given that more β1-type NiO phase was formed with the doping of Fe, the Ni–3Fe/Al2O3 catalyst reached the highest activity and stability.